This invention relates to a process and a chemical composition useful in the preservation of wood and wood fiber products against damage caused by insects such as termites, as well as other destructive organisms including fungus and bacteria. A variety of techniques are known in the art directed to the preservation of wood and wood-containing products.
For instance, a physical barrier such as paint may be applied to the surface of the wood to prevent injury or attack by a destructive organism. However, a paint barrier is not suitable to use as an extended barrier for wood surfaces which are in contact with the soil. Additionally, painted wood surfaces may lack the durability needed for extreme environmental conditions such as an outdoor deck material.
Other wood preservatives have included solid based applications of various toxins designed to kill organisms that may attack the treated wood. In particular, the use of aqueous salt compounds such as chromated copper arsenate (CCA) has been widely used in the pressure treated lumber industry. However, the use of toxic compounds and aqueous salt compounds has been linked to environmental concerns related to the contamination of the environment as salts of heavy metals and/or other toxic compounds are leached into the surrounding soil and water.
In addition to the environmental concerns brought about by the use of heavy metal salts and/or other wood preserving toxins, the leaching of materials from the wood lessens the resistance of the wood to decay. As such, over time, the treated wood may become less resistant to decay as the preservatives leach into the environment.
A variety of wood preservative techniques, chemicals, and related technology may be found in reference to the following U.S. patents and which are incorporated herein by reference.
U.S. Patent Documents3775047November, 1973Weston 8/373985921October, 1976Rowell et al 427/317I4329383May, 1982Joh 428/364780341October, 1988Chow 427/4404804384February, 1998Rowell et al 8/1815470614November, 1995Chin et al 427/440
Accordingly, there remains room for improvement and variation in the art with respect to processes and chemicals used in the treatment of wood products.